1. Field of the Invention
The present invention relates to a feedthrough capacitor and a method for producing the feedthrough capacitor.
2. Related Background Art
In general, a feedthrough capacitor is provided with signal internal electrode layers and ground internal electrode layers alternately arranged in a capacitor element body. The signal internal electrode layers and the ground internal electrode layers exist so as to penetrate the interior of the capacitor element body, and connect terminal electrodes and ground electrodes arranged so as to be opposed to each other on the end faces of the capacitor element body. An example of the feedthrough capacitor of this type is the one described in Japanese Patent Application Laid-open No. 9-55335. This conventional feedthrough capacitor has a structure in which at least three ground internal electrode layers are laid between the signal internal electrode layers.
Incidentally, it is important in the feedthrough capacitor that a gap amount between the ends of the signal internal electrode layers in a direction intersecting with the direction of penetration thereof, and the exterior surface of the capacitor element body be maintained at an appropriate value. If this gap amount is insufficient, for example, in a case where the terminal electrodes and others are formed on the end faces of the capacitor element body by a wet plating method, a plating solution could intrude into the signal internal electrode layers to degrade the reliability of the element. There is another possibility that a desired capacitance could not be achieved because of variation in the area of opposed portions where the signal internal electrode layers are opposed to each other, when viewed from the stack direction of the capacitor element body.
The multilayer electronic component described in Japanese Patent Application Laid-open No. 9-312237 is provided with projecting detection patterns in the lead portions of the internal electrodes, and whether the gap amount is abnormal or not is determined based on the shape of the detection patterns exposed in the capacitor element body after cut. However, since this technique is to determine whether the gap amount is abnormal or not, by observation of appearance of the capacitor, it has a problem that it becomes harder to discriminate an abnormal pattern from a normal pattern as the element becomes smaller.